Electrical connectors provide signal connections between electronic devices using signal contacts. Often, the signal contacts are so closely spaced that undesirable interference, or “cross-talk,” may occur between adjacent signal contacts. As used herein, the term “adjacent” refers to contacts (or rows or columns of contacts) that are next to one another. Cross-talk may occur when one signal contact induces electrical interference in an adjacent signal contact due to intermingling electrical fields, thereby compromising signal integrity. With electronic device miniaturization and high-speed, high-signal integrity electronic communications becoming more prevalent, the reduction of cross-talk becomes a significant factor in connector design.
One commonly used technique for reducing cross-talk is to position separate electrical shields, in the form of metallic plates, for example, between adjacent signal contacts. The shields may act as a ground connection, thereby reducing cross-talk between the signal contacts by preventing the intermingling of the contacts' electrical fields. The metallic plates may be used to isolate an entire row or column of signal contacts from interfering electrical fields. In addition to, or in lieu of, the use of metallic plates, cross-talk may be reduced by positioning a row of ground contacts between signal contacts. Thus, the ground contacts may serve to reduce cross-talk between signal contacts in adjacent rows and/or columns.
As demand for smaller devices increases, existing techniques for reducing cross-talk may no longer be desirable. For instance, electrical shields and/or ground contacts consume valuable space within the connector, space that may otherwise be used to provide additional signal contacts and, thus, increase signal contact density. Furthermore, the use of shields and/or ground contacts may increase connector cost and weight. In some applications, shields are known to make up 40% or more of the cost of the connector.
In some applications, electrical connectors may be used to couple two or more devices with connecting surfaces that do not face each other (e.g., printed circuit boards that are perpendicular to each other). Such applications typically require right-angle connectors, which may use signal contacts with one or more angles. The total length of each signal contact in the connector may depend on the degree and/or the number of its angles. These variables are usually determined by the signal contact's relative position in the electrical connector. Consequently, some or all of the signal contacts in an angle connector may have different lengths. Signal skew typically occurs when two or more signals are sent simultaneously but are received at a destination at different times. Therefore, a need exists for a high-speed electrical connector that minimizes signal skew and reduces the level of cross-talk without the need for separate internal or external electrical shielding.